Traffic signal



Oct. 27, 193k, G. c. WALKER 1,829,025

TRAFFIC SIGNAL Filed 001'.. 6, 1950 Groes C h/fn. KEA? Patented Oct. 27,1931 UNITED STATESPATENT OFFICE 'f GEORGE C. WALKER, OF WAYNE MICHIGAN,ASVSIGNOR 0F ONE-HALF T0 THOMAS M. LUCXIN G, OF DETROIT, MICHIGANTRAFFIC SIG\NAL 'i- Applioation led October 6, 1930. Serial No. 486,541.

This invention relates to a traffic signal, and has to do particularlywith novel means for indicating the approximate time before a change insignals.

In standard traffic signals now generally in use, the change from onesignal to another is instantaneous so that unless the motorist isunusually familiar with each individual traffic light the change intraffic in very slow 1o and confusing. 'Attempts have beenmade toindicate time of change by passing various indica over the face ofthesignal and by varying the extent of closure of the signal opening, butsuch devices have usually been more or less complicated.

The primary object of the present invention .is to indicate theapproximate duration of a certain signal, or, in other words, the timeremaining before the change of the signal, by shaping the lightindicating field itself so that its inherent shape passing by the signalopening serves as a timing means. In this case. the timing may beindividually controlled at each traffic signal and is preferablyobtained by a rotating indicating field', the light source remainingfixed.

Another feature of the invention resides in the provision of means forinstantly changing the signal from one color to the next as the existentindicating field approaches the end of its movement past the signalopening. In this case. the blank spaces between adjacent rotatingindicating fields are eliminated and a full indicating field covers theopening until the next indicating field reaches its effective position.

In the drawings:

Fig. l is a vertical sectional View of a traffic signal embodying thefeatures of the present kinvention and illustrating one means forraising and lowering the intermediate shutter structure.

Fig. 2 is a somewhat diagrammatic sectional view showing the shutterarrangement in neutral position with the light field uncovered.

Fig. 3 is a view similar to Fig. 2 but showing the green shut-ter inraised position to fill in the space between the red rotating field andthe green rotating field.

Figs. 4 and 5 illustrate a similar development to Figs. 2 and 3, butwith the shutter unit in neutral position with the green rotatingfieldshowing and in lowered position with the red shutter intervening betweenthe two fields.

Fig. 6 is an elevation of a traffic signal embodying the presentinvention and showing the narrowing indicating field moving past thesignal opening. The gist of the present invention resides 1n a movingindicating field the shape of which visibly indicates the approximatetime such field will remain before a given opening. Various types ofstructure and various mechanical means may be utilized for rotating andcontrolling the operation of the predetermined shaped indicating fieldsand in Fig. l I have illustrated one form of device embodying thepresent invention.

Any sultable housing l may be provided with a plurality of apertures 2which may be termed signal openings. A light source 3 may bestationarily supported from the top of the signal housing as best shownin Fig. l,

and a cylindrical rotatable drum 4 preferably surrounds this lightsource 3. The drum 4 may be rotated by any suitable means 5 which mayconsist of a motor or similar device the speed of which may be regulatedat each particular traffic signal or controlled from a common remotepoint.

rIhe drum 4 is preferably provided with apertures 6, such apertureshaving a special shape, as best illustrated in Fig. l, and being backedby a transparent colored means 7 such as Celluloid or the like to formindicating fields. The length of each indicating field and the degree oftaper may, of course, vary with different installations and particularlywith the size of such installations. In the ordinary standard trafficsignal it will be obvious that diametrically opposite indicating fieldswill be of similar colors.

If desired, the horizontally tapered indicating fields 6 may be rotatedpast the apertures 2 without the use of any intervening shutter or thelike. As each indicating field narrows down towards a point, it will beobvious to any observer that a change of signals is about to take place.As a wide signal indicated b of different color starts across the signalopening this will indicate a change of signal.

To positively indicate the change in signals I prefer to use a shutterarrangement so that as the changing indicating fiel gradually comes downloward a point, indicating that the change is about to take placa-theshutter will immediately and quie ly cover the opening and such shutterwill be of the same color as the oncoming indicating field with theresult that when the oncoming indicating field assumes its positionrelative to the signal opening the shutter may be moved so as to allowthe changing shape of the indicating field to indicate the approximatetime of change of signals.

One form of shutter structure is illustrated in Fig. 1 and diametricallyin Figs. 2 to 5. This shutter consists .of a vertically movable c linder8, the vertical movement of said s utter being assisted by means ofsuitable grooves 9 formed in the housing l. Each cylindrical shutterunit may be cut-away to form three apertures 10, 1l, and 12, theaperture 10 being covered with red transparent material corresponding tothe material used in forming the indicating field 6, the aperture 11bein open and the aperture 12 being covered wit green transparentmaterial.

The drum 4 may be provided with a suitable cam groove 13 and thecylinder shutter member 8 provided with a suitable pin 14 adapted to beactuated by said cam groove. As the drum 4 is rotated at its regularspeed it will be obvious that the cylindrical shutter unit will be movedup an down according to the particular part of the shutter which is tocover the signal opening. In ordinary practice the central horizontalpart of the cam groove will cause the shutter to remain in neutralposition, such as shown in Figs. 2 and 4, a relatively longI time, andin the top and bottom positions a relatively short time. The same lightsource 3 will provide sufficient light to illuminate the portions 10 and11 of the shutter when such portions cover the I signal opening.

The size of the signal opening 2 may vary considerably and is preferablysmaller than the apertures 10, 11, and 12 of the shutter. Whether a camgroove, or other means, is used to operate the shutter such shutter ispreferablyactuated to cover the opening at a time when the passingindicating field narrows down to a point. The shutter drops across theopening between the time the end of the indicating field leaves the edgeof the opening and the time it reaches the center of such opening, thepreferred operation being at the very instant that the tail end of theindicating field reaches the first edge of the opening.

It will thus be seen that I have provided a traffic light the time ofchange of which is a predetermined permanently shaped indicating fieldmovable relative to a stationary signal opening, The mechanism is verysimple and lnexpensive and the timing of each signal may be regulated bymerely increasing or decreasing the speed of movement of the Adrumcarrying the indicating fields. The intermediate or yellow signal isdispensed with and but one light source is necessary.

It will be understood that a plurality of independent light sources maybe embodied within the signal with the result that one or more of saidlight sources may fail without impairing the efficiency of the signalindicating means. Thus if my signal device is equipped with threesources of light as the ordinary traffic signal, it will be obvious thatI obtain a safety factor three times aslg'reat as that of the usualtrafiic signal.

What I claim is:

1. A traffic signal of the type described, comprising a movableindicatin field, certain sides of which are shaped to lndicate the rateof change of said indicating field.

2. A signal comprising a relatively movable signal o ening andindicating field, said indicating eid being shaped to change its visiblecontour and indicate the time of change during said relative movement.

3. A signal comprising a relatively movable signal opening andindicating field, one of said members being shaped to visibly indicateby a change in contour the approximate time of change during saidrelatlve movement.

4. A trafiic signal comprising a stationary light source, a fixed signalopening and a specially shaped indicating field positioned between thelight source and said opening and movable relativeto the opening tovisibly indicate by a changing contour the approximate time said fieldremains.

5. A traffic signal com rising movable indicating fields havinggradually changing contours to visibly indicate the time le'ft before achange in signal and separate means for covering the space between theindicating fields.

6. A traiiic signal comprising a stationary light source and a housinghaving an opening and a plurality of indicating fields rotatable pastsaid opening, said indicating fields being shaped to visibly indicatethe approximate rate of change of a given indicating field, and signalmeans in the form of a shutter member over said opening during thechange between one signal and another signal.

7. A traffic signal comprising a stationary light source and a housinghaving an opening and a plurality of indicating elds rotatable past saidopening, said indicating fields being shaped to visibly indicate theapproximate rate of change of a given indicating field, and signal meansin the form of a shutter memindicate the approximate time saidindicating field takes to pass said opening.

9. Signal means comprising a signal opening and an indicating fieldmovable past said opening, said indicating field being shaped so as togradualy merge towards a central point as it passes horizontally by saidopening whereby to indicate the approximate time said indicating fieldtakes to pass said opening.

10. A signal device comprising a light' source, a signal opening, anindicating field illuminated by said light source, said indicating fieldand said signal opening being relatively movable and shaped whereby saidrelative movement will cause a change in the shape of the visible partof lthe indicating field to indicate the approximate time of change.

11. A signal device comprising a light source, a signal opening, anindicating field illuminated by said light source, said indicatin fieldand said signal opening being relative y movable and shaped whereby saidrelative movement will cause a change in the shape of the visible partof the indicating field to indicate the approximate time of change, anda transparent shutter means for coverin said opening at a certainpredetermined time during the relative movement between said indicatingfield and opening.

12. A signal device comprising a light source and a rotatable indicatingfield, said indicating field havin angularly positioned sides taperingtowar s apoint whereby to indicate the approximate time of changebetween one indicating field and the next.

13. A signal device comprising a light source, a single visible signalopenin for each particular direction, a colored in icating field havinga predetermined shape, and means for cansino` relative movement betweenthe indicating field and said single opening whereby the shape of saidindicating field graduall changes to visibly indicate the time leftbefore a change in si al.

14. A signal device comprising a ight source, a visible signa-l openingfor each particular direction, an indicating field movable past said oening,vand means formin a part of said in icating field for visiblyindicatin the approximate rate of change and time le before a change insignal.

15. A signal device comprising a light source, a visible signal o eningfor each particular direction, an indicating field movable` pastsaid oening and means forming a part of said indicating field and graduallychanging in dimensions for visibly indicatin the approximate rate ofchange and time le fore a change in signal.

In testimony whereof I aflix my signature.

GEORGE C. WALKER.

Ilan

